The rate at which data are transmitted through communication networks has dramatically increased in recent years. Fueled by progresses achieved in fiber and optoelectronic devices and techniques such as DWDM (Dense Wavelength Division Multiplexing), which allow multiplying the bandwidth of a single fiber by merging many wavelengths on it, telecommunications and networking industry had to develop devices capable of routing and switching the resulting huge amount of data that converge and must be dispatched at each network node. Typically, routers and switches situated at those network nodes have to cope with the requirement of having to move data at aggregate rates that must be expressed in hundredths of giga (109) bits per second while multi tera (1012) bits per second rates must be considered for the new devices under development.
If considerable progress have been made in optoelectronic, which allowed reaching this level of performances in the transport of data from node to node, it remains that switching and routing of the data is still done in the electrical domain at each network node. This, essentially, because there is no optical memory available yet that would permit storing temporarily the frames of transmitted data while they are examined to determine their final destination. This must still be done in the electrical domain using the traditional semiconductor technologies and memories.
Improvements in semiconductor processes are enabling the making of integrated circuits of increasing size and complexity. Combined with the complexity of the multi-channels, multi-emitters and receivers capabilities requested in communication systems, whole electronic communication systems represent an environment that must be tested for reliability reasons and also to determine their performances. As a consequence, adapted methods have been developed for testing the behavior of such systems.
A well known solution consists in sending a flow of data from an emitter to a receiver and changing the active channel through which data is transmitted as illustrated on FIG. 1. In this example, communication system 100 comprises an emitter 105, a receiver 110 and a set 115 of n possible channels referred to as 120-1 to 120-n. Testing communication system 100 according to this method consists in sending a first flow of data from emitter 105 to receiver 110 through channel 1, then sending a second flow of data from emitter 105 to receiver 110 through channel 2 and so on until all the channels have been used. The following test that is done consists in sending a flow of data from emitter 105 to receiver 110 through any channel and commuting to another channel during the transmission. Generally, the data that are used to test the system, i.e. the data sent from emitter 105, are stored in a first file and data received at receiver 110 are stored in a second file. At the end of the test, both files are compared to check that data has not been altered, lost, duplicated nor desequenced.
However, due to the complexity reached by such system, the amount of data used during the communication system test requires huge files and the analysis, generally conducted when the test is completed, takes time. Furthermore, since the analysis is generally done at the end of the test, information relative to the environment state when an error has occurred may be lost. Finally, the communication system being tested by analyzing the behavior of couple of emitter/receiver one after the other, it is not tested in real conditions wherein several channels may be used simultaneously to transmit data from different emitters to different receivers.